1. Field of the Invention
This invention relates generally to a power driven paper take-up mechanism and in particular to a mechanism which allows a single slip drive system to simultaneously provide the appropriate driving force to one or more separate paper rolls.
2. Description of the Prior Art
There are basically two types of power-driven paper take-up devices. The first type is a positive drive system which drives a section of a paper roll intermittently, starting when there is paper to take up and stopping once the slack is eliminated. This type of system, of necessity, requires either a sensor that determines when slack exists in the section of paper between the printing elements and the take up area, or that the system be sychronized with the printing mechanism. The second type of take-up device is a slip drive system. A slip drive system utilizes either a limited friction device, such as a roller, which rotates in a direction such that the contact between the roller and paper takes up the slack in the paper, or a slip device between a drive motor and a non-slipping roller.
Each of these systems, however, is not easily adapted for use especially on a multiple roll printer. One disadvantage of the intermittent type system is that a separate system is required for each roll of paper of a multiple paper roll printer.
If a single slip type system is used for multiple paper rolls, those paper rolls adjacent to a roll being spaced by the printer mechanism may also be advanced, thereby causing blank spaces between lines and severely reducing paper economy. Accordingly, it is desireable to provide a single system that will simultaneously provide the proper driving force to multiple paper rolls without producing blank spaces between successive print lines in each roll.